Truing device for peripheral type grinding wheels



Oct. 14, 1958 c. STELMACHOWSKI TRUING DEVICE FOR PERIPHERAL TYPE GRINDING WHEELS Filed Dec. 26, 1956 E11 2 22in? Z'ar/ fife/mach awsk l United States Patet TRUING DEVICE FOR PERIPHERAL TYPE GRINDING WHEELS Carl Stelmachowski, Chicago, Ill., assignor to Super-Cut, Inc., Chicago, Ill., a corporation of Illinois Application December 26, 1956, Serial No. 630,675

7 Claims. (Cl. 51-169) The present invention relates to an improved combined mounting and truing device whereby a cutting or abrading tool of the rotary type may be operatively mounted on a central drive shaft or spindle and the peripheral regions thereof brought into precise axial coincidence with the axis of rotation of the spindle.

The truing device of the present invention has been designed for use primarily in connection with the truing of peripheral type diamond grinding wheels. The invention is, however, capable of other uses and the same way, if desired, with or Without suitable modification, be employed for truing and/or balancing shaft or spindlemounted abrasive or other rotary tools which differ widely in their construction and design, as well as in the use to which they may be put. Irrespective, however, of the specific application of the present truing device, the essential features thereof are at all times preserved.

In the operation of peripheral type diamond grinding wheels, only extremely small eccentric tolerances are perrnitted between the axis of the central drive shaft or spindle, both from the standpoint of accurate control of the desired work contour and of vibrational eliects in the grinding wheel itself during free rotation thereof. Thus, where there is any discrepancy or lack of coincidence between the axis of the peripheral ring-like diamond matrix of the wheel and the axis of the central mounting opening in the wheel, the grinding wheel cannot be mounted for proper operation on the central drive spindle or on the adaptor associated with such spindle and, at least, for certain types of precision work, as, for example, in chip breaker operations, the wheel must be discarded. Similarly, where there is a comparatively wide tolerance between the diameter of the spindle; or the cylindrical mounting surface of the'grinding wheel adaptor and the diameter of the central opening in the grinding wheel, it is diflicult to mount the wheel, on the spindle in a condition of either trueness or balance, or both, and much time is consumed in an effort to obtain such trneness and balance.

The present invention is designed to overcome the above-noted limitations that areyattendant upon theuse of conventional peripheral diamond grinding wheels, and, toward this end, it contemplates the provision of a novel mounting for the grinding wheel whereby the latter may be operatively mounted on the drive spindle and adjusted thereon through very fine limits of adjustment and thereby brought to a precise position of trueness and condition of balance.

The provision of a grinding wheel mounting of the character briefly outlined above being among the principal objects of the invention, it is a further object to provide an adjusting means for varying the radial position of the grinding wheel on its drive spindle or adaptor so that the eccentricity of the former may be brought within tolerable limits with a minimum of effort on the part of the operator and whereby the adjusting meansis conveniently accessible to the operator at the time of ICC initial installation of the grinding wheel or at any time thereafter.

It is a still further object of the invention to provide a truing device of this character wherein the adjustments may be made with the grinding wheel installed on the spindle without requiring disassembly of the parts, removal and reapplication of the wheel from and to the spindle, or rearrangement of the various parts of the device.

Yet another object of the invention is to provide such a truing device which utilizes plural independent adjusting means which bear to one another an interdependent adjusting function and each of which may be independently locked in an adjusted position when the proper adjustment for that particular adjusting means has been ascertained and effected.

It is a still further object to provide a combined mounting and truing device for peripheral type diamond grinding wheels wherein the various parts thereof, and particularly the adjusting instrumentalities associated with the same, are devoid of threaded parts which are expensive to machine and which may, under certain circumstances, cause binding of the parts and consequent difiiculty in elfecting the necessary adjustment.

With these and other objects in view which will become more readily apparent as the nature of the invention is better understood, the same consists in the novel construction, combination and arrangement of parts shown in the accompanying single sheet of drawings forming a part of this specification.

In these drawings:

Fig. 1 is a front elevational view, partly in section, of a peripheral type grinding wheel showing the same operatively mounted on a central adaptor by means of the present truing device;

Fig. 2 is a side elevational view, partly in section, of the structure shown in Fig. l;

Fig. 3 is a quarter sectional view taken substantially along the line 3-3 of Fig. 2; and

Fig. 4 is a fragmentary detail sectional view taken on a radial plane transversely through a modified form of the truing device.

Referring now to the drawings in detail and in particular to Figs. 1 and 2, a conventional peripheral type diamond grinding wheel is designated in its entirety at 10 and includes the usual wheel body or annulus 12 having a central mounting or arbor opening 14 formed therein. A peripheral matrix assembly 16 consisting of crushed or fragmented diamonds is carried at the outer circular edge of the wheel body 12. The grinding wheel 10 is shown as being mounted on a conventional adaptor 18 having a rearwardly disposed radial clamping head 20 and a threaded shank portion 22 by means of the truing and mounting device of the present invention and which will presently be described in detail. The adaptor 18 is carried at the outer tapered end 24 of adrive shaft or spindle 26 associated with a conventional grinding machine which may be of any suitable type. A clamping nut 30 which is countersunk in the adaptor 18 and threaded as at 32 on the reduced end of the spindle 26 serves to secure the adaptor on the spindle for rotation in unison therewith. As shown in Figs. 1 to 3, inclusive, the mounting device is designated in its entirety at 34 and is comprised of three annular parts including a rear clamping ring 36, a front clamping ring 38 and a clamping nut 42. The device further includes a series of adjusting elements or centering devices 44 of which there are preferably four in number although a greater or lesser number of such elements may be employed if desired. i

As best seen in Fig. 2, the rear clamping ring 36 is in the form of a relatively thick circular plate having a central hub portion 46 of uniform thickness presentinga flat annular shoulder 50 formed on the adaptor. head.20.. and

a cylindrical outer surface 51. The outer portion 54 of the ring 36 is of less thickness than the thickness of the hub'portion 46-and hasformed thereon .aL forwardly facing circular rib presenting a flat annular clampingshrface 55 adaptedto bear against the rear sideof the-wheel body 12. The front clamping ring 38 is similar inits-design'to the ring 36 and presents a flat radial. front face 57; The ring 38 has formed thereon a rearwardly facing? circular rib presenting a flat annular clamping surface 62% which opposes the surface 55' and is adaptedto bear against the front side of the wheelbody 12'so that the latter may be clamped between the two surfaces. 55 and 62: The clamping nut 42 is adapted to be tightenedon the threade'd shank portion 22 of the adaptor 18: to draw'th'e various parts together, thus clamping the two rings 36 and 33 between the nut 42 and shoulder 50 on the adaptor head and, in turn, clamping the inner peripheral regions of the wheel body between the surfaces 55 and 62 in selected positions of adjustment of the wheel under the control of the various clamping elements 44 in a manner that will subsequently be made clear;-

The adjusting elements 44 are identical in design and each is in the form of a short cylindrical rod 64 the medial region of which is formed with an annular groove 66 and having an enlarged circular head 68 formed thereon which is eccentrically disposed with respect to the axis of the rod 64-. Each rod 64 extends into an opening or transverse bore 70 formed in the rear ring- 36, four such openings beingprovided with the various openings and which may be applied to the element 44 through an access opening or hole 76 formed in the clamping ring 38 in alignment with the opening 70. When the various clamping elements 44 are operatively positioned in the assembly, the eccentric head portions 68 thereof are-interposed between the inner periphery or rim of the mount- 4 ing opening 14 of the grinding wheel 10 and the outer cylindrical surface 51 of the hub portion of the rear clamping ring 36 and are designed for camming contact with the rim 14 upon turning movement of the elements 44. a

The clamping nut 42 may be of the circular type and is formed with a pair of diametrically opposed spaced holes 75 therein designed for cooperation with a suitable tool such as a spanner wrenchor the like and by means of which the nut may be tightened on the threaded shank portion 22" ofthe adaptor 18.

In the operation of the above described mounting device 34, the grinding wheel 10 is first mounted on the adaptor 1 8 with the central mounting'opening 14 therein encircling the four'circular head portions 68 and'with the clamping nut 42 drawn up loosely against the forward surface 57 of the front clamping ring 38. It is then necessary only to insert a screwdriver type tool into and through one or more of the holes 76 inthe ring 38" and into registry with the slot or slots 74 for proper cooperation with one or more of the adjusting elements 44 so that the latter may be turned in one direction or the'other and the enlarged heads 68' thereof brought into camming engagement with the rim of the opening 14. Since the grinding wheel bodyor annulus is only loosely clamped between the opposed surfaces and 62, turning of the various adjusting'elements 44 may beutilized to bring the grinding wheel 10 to a precise adjustment wherein an I the wheel.

.4 theaxisofthespindle 26. Truing of the grinding wheel in this manner will ordinarily compensate to a large extent for any unbalanced forces which might otherwise arise in the rotating wheel and the latter will be in perfeet balance, as well as being true on the driving spindle While adjusting operations are in effect as described, turningiof any one. of the adjusting elements 44 in its respective bore will bring the circular but eccentrically mounted enlarged head portion of the element into camming engagement with the rim of the opening 14 and apply a direct radial thrust to the grinding wheel or, depending upon the particular setting of the other elements 44, applying a vectorial component of thrust to Experience will dictate the particular order of adjustment of the various elements as well as the extent to which each element shall be turned to effect the desired adjustment; As each. adjusting. element is brought to its correct adjusted position, or as it is brought. to any given. temporary position, utilizing a. trial and error method of adjustment, it may be locked in its adjusted position by tightening of the respective setscrew 72 associated therewith against the bottom of the annular groove 66 formed in the element 44. Either the same adjusting tool which is' employed for turning the various elements 44 or a separate adjusting tool may be employed for manipulation of the setscrews 75. The adjustment of the last element 44 in the'series will effect" a four-way binding of the grinding wheel 10 and the latter will be securely locked in its adjusted position. After the necessary-adjustments of. the various adjusting elements 44 has been'made, the clamping screw 42 may be tightened on the adaptor and against the surface 57 of the front ring 38 and the machine set into operation.

In. the form ofthe invention shown in Fig. 4, the clamping parts, i. e., the front and rear clamping rings 38 and 36, respectively, remain substantially the same as in the previously described form of the invention shown in Figs. 1 to 3, inclusive. In this instance, however, an intermediate ring or collar 140 is fitted within the central or mounting opening 14 of the grinding wheel body 12 and encompasses the circular enlarged head portions 68 of the various adjusting elements 44 and is loosely disposed between the opposed inner faces of the two clamping rings 36 and 38 so that it, instead of the inner rim of the opening 14, receives the radial or vectorial thrusts of the adjusting elements 44. Bodily shifting movement of the collar 80 will, of course, impart such shifting movement to the grinding wheel 10 as a whole. Otherwise, the, details of construction and the operation of the form of the invention shown in Fig. 4 remain substantially the same as that shown in Figs. 1 to 3, inclusive, and, to avoid needless repetition of description, similar characters of reference of a higher order have been applied to the corresponding parts in Fig. 4.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawing or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit of the invention. Only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having'thus described the invention what I claim as new'and desire to secure by Letters Patent is:

1. In a device for operatively mounting a peripheral type grindingwheel or the like having a wheel body provided with a mounting opening therein on a machine spindle between a shoulder normal to and rotating withthe spindle and a clamping nut on the forward end of the spindle, in combination, front and rear clamping rings on opposite sides of the wheel body and surrounding the spindle between said shoulder and nut in concentric relation with respect to the spindle and having their inside surfaces in engagement with the opposite faces respectively of the wheel in clamping relation thereto under the influence of said clamping nut, and a unitary adjusting element rotatably mounted in one of said clamping rings in the medial regions thereof and having a cam surface interposed axially "between said clamping rings at at least three circuinferentially spaced regions therearound with the cam surface thereof lying in the general plane of the wheel body within the mounting opening thereof in close proximity to the rim of said opening so that said rim encircles all of said cam surfaces, each adjusting element including a cylindrical shank extending axially into and rotatably mounted in one of the clamping rings for turning movements in opposite directions and an enlarged head on the periphery of which said cam surface is formed, said head being designed for frictional sliding camming engagement with said rim of the mounting opening upon turning movement of the adjusting element to exert outward radial thrust on the grinding wheel body tending to displace the same.

2. In a device for operatively mounting a peripheral type grinding wheel or the like on a machine spindle, the

- combination set forth in claim 1 wherein said adjusting elements are four in number and are circumferentially spaced 90 apart. 7

3. In a device for operatively mounting a peripheral type grinding wheel or the like on a machine spindle, the combination 'set forth in claim 1, including, additionally, locking means for each adjusting element for releasably locking the same in a selected position of adjustment.

4. In a device for operatively mounting a peripheral type grinding wheel or the like on a machine spindle, the combination set forth in claim 1 wherein the other clamping ring is formed with a series of access openings therethrough in axial alignment with a respective clamping device.

5. In a device for operatively mounting a perpiheral type grinding Wheel or the like on a machine spindle, the combination set forth in claim 1 wherein said enlarged head portion on each adjusting element is of circular configuration and is eccentrically disposed with respect to the axis of the cylindrical rod on which said head portion is formed.

6. In a device for operatively mounting a peripheral type grinding wheel or the like having a wheel body provided with a mounting opening therein on a machine spindle between a shoulder normal to and rotating with the spindle and a clamping nut on the forward end of the spindle, in combination, front and rear clamping rings on opposite sides of the Wheel body and surrounding the spindle between said shoulder and nut in concentric relation with respect to the spindle and having their inside surfaces in engagement with the opposite faces respectively of the wheel in clamping relation thereto under the influence of said clamping nut, and an intermediate mounting ring fitting tightly within said mounting opening in the grinding wheel body, a unitary adjusting element rotatably mounted on one of said clamping rings in the medial regions thereof and having a cam surface interposed axially between said clamping rings at at least three circumferentially spaced regions therearonnd with the cam surface lying in the general plane of said intermediate ring and within the confines of the latter in close proximity thereto so that said intermediate ring encircles all of said cam surfaces, each clamping member including a cylindrical rod rotatably mounted in one of said clamping rings for turning movements in opposite directions and an enlarged head on the periphery of which said cam surface is formed, said head being designed for frictional sliding camming engagement with said intermediate ring upon turning movement of the adjusting element to exert outward radial thrust on said latter ring tending to displace the latter and consequently the grinding wheel body.

7. In a device for operatively mounting a peripheral type grinding wheel or the like on a machine spindle, the combination set forth in claim 6 wherein said enlarged head on the adjusting element is of circular configuration and is eccentrically disposed with respect to the axis of said cylindrical rod.

References Cited in the file of this patent UNITED STATES PATENTS 68,876 Harrington Sept. 17, 1867 626,962 Bird June 13, 1899 763,469 Ellis June 28, 1904 2,407,222 Boyce Sept. 10, 1946 

